Bystander initiated automated external defibrillator shocks improve survival and functional outcome
It is now well established that bystander initiated cardiopulmonary resuscitation (CPR) greatly increases the chances of survival in out of hospital cardiac arrest. This has lead to large scale training of lay persons in CPR in the hope of increasing survival in out of hospital cardiac arrest. Now we have an extension to the service: use of automated external defibrillator (AED). AED is being increasingly deployed in public places like airports, railway stations and malls. Use of AED is now included in Basic Life Support (BLS) classes on CPR for lay persons. Hence the persons who can use it is on the rise, though actual use in a cardiac arrest situation may have some social barriers. Study by Pollack and colleagues (Resuscitation Outcomes Consortium Investigators) published in Circulation  has evaluated the role of AED shocks in those who have shockable rhythms in the public out of hospital cardiac arrests (OHCAs). Though the overall presence of shockable rhythms in OCHA is only about one fourth, it is about 60% in public OHCAs. The primary outcome was discharge with normal or near normal functional status with a modified Rankin score of two or less. Of the 4115 observed public cardiac arrests (which constituted only 8.3% of the total out of hospital cardiac arrests), 2500 (60.8%) had shockable rhythm. Bystander initiated shock was given to 18.8% of the shockable arrests. Discharge with good functional outcome occurred in 57.1% vs 32.7% in those who did not receive a bystander AED shock. Survival to discharge was also higher in this group (66.5% vs 43%). They also noted that the benefit with bystander initiated AED shock increased progressively with increasing emergency medical services response time.
Authors suggest that availability and use of AEDs in public places should be enhanced, more so in locations where the response time of emergency medical service is longer.
- Pollack RA, Brown SP, Rea T, Aufderheide T, Barbic D, Buick JE, Christenson J, Idris AH, Jasti J, Kampp M, Kudenchuk P, May S, Muhr M, Nichol G, Ornato JP, Sopko G, Vaillancourt C, Morrison L, Weisfeldt M; ROC Investigators. Impact of Bystander Automated External Defibrillator Use on Survival and Functional Outcomes in Shockable Observed Public Cardiac Arrests. Circulation. 2018 May 15;137(20):2104-2113.